BSM fits for rare B decays

International audience; The LHCb experiment has made several measurements in $b \to s$ transitions which indicate tensions with the Standard Model predictions.We examine how the significance of the tensions in $B \to K^* \mu^+\mu^-$ observables depend on the various theory implementations of the long-distance effects.We also consider a general parameterisation, consistent with the analyticity structure of the amplitudes and make a statistical comparison to find whether the most favoured explanation of the anomalies is new physics or underestimated hadronic effects.Furthermore, assuming the source of the anomalies to be new physics, to get a fair view of how significantly favoured it is, we perform a global fit to all the Wilson coefficients which can effectively receive beyond the Standard Model contributions.